In two-door vehicles with only one passenger door per side for gaining access to both the front and back seats, the seat backs of the front seats typically pivot about the seat cushions so that the seat backs may be tilted forwardly to enable access to the back seats. In addition, in order to comfortably seat people of various sizes, the front seat is mounted on tracks which cooperate with an adjustment mechanism to enable the front seat to be moved forwardly and rearwardly. Typically, a handle which extends from beneath the front seat is activated by a seated passenger such that the seat is released from its fixed position and allowed to move on its tracks. When the passenger finds the most comfortable position for the seat, the handle is released and the seat is fixed at its new position on the tracks.
More recently, the adjustment mechanism for a front seat has been made responsive to forward tilting of the seat back so that such tilting releases the adjustment mechanism and allows the seat to move forwardly on the tracks to an entry position in order to provide more room for passengers entering the rear seats of the vehicle. This feature makes entry and exit to and from the back seat easier but, in many vehicles, it also requires the passenger in the front seat to re-adjust the front seat position each time the seat back is tilted by passengers entering or leaving the back seat.
Drouillard et al U.S. Pat. No. 4,440,442 discloses a seat adjusting mechanism in which the seat may, without trial and error adjustment, be re-set to its previous functional position when the seat is moved rearwardly after having been shifted forwardly to its entry position. The Drouillard et al adjusting mechanism, however, requires three sets of tracks, namely, a lower track fixed to the floor of the vehicle, an upper track fixed to the seat of the vehicle and an intermediate track slidably supported on the lower track and slidably supporting the upper track.